there's also a security setting in win 7 that restricts you from capturing web objects, please first check as sankalp told you, if still doesn't work then follow these steps:
Open Control Panel > User Accounts > Change User Account Control Settings > Move the bar all the way to the bottom ( "Never Notify" )
hopefully it'll yield some results for you
Open Control Panel > User Accounts > Change User Account Control Settings > Move the bar all the way to the bottom ( "Never Notify" )
hopefully it'll yield some results for you
